// source: https://stackoverflow.com/a/46488389
//
var question = function(q) {
	return new Promise( (res, rej) => {
		const stdin_proc = process.openStdin()
		process.stdout.write(q)
		function catchInput(text) {
			const ans = text.toString().trim()
			res(ans);

			stdin_proc.pause(); // stop reading
		}
		// We use once to avoid "MaxListenersExceededWarning" error
		stdin_proc.once('data', catchInput);
	});
};

//
(async function main() {
	var answer;
	while ( answer != 'yes' ) {
		answer = await question('Are you sure? ');
	}
	console.log( 'finally you are sure!');
})();